title: Impact of familial risk and mammography screening on prognostic indicators of breast disease among women from the Ontario site of the Breast Cancer Family Registry.
abstract: Although several studies have found screen-detected cancers in women with familial breast cancer risk have favorable prognostic features compared with symptomatic cancers, the impact of level of familial risk is unknown. A cohort of 899 first-degree female relatives of cases of breast cancer from the Ontario site of the Breast Cancer Family Registry was followed for 2 years. Logistic regression analyses compared diagnoses of breast cancer or benign breast disease (BBD) between women at high (n = 258, 28.7 %) versus low/moderate (n = 641, 71.3 %) familial risk. Similar analyses compared prognostic features of invasive cancers and BBD by level of familial risk and mammography screening status. Among 899 women, 44 (4.9 %) were diagnosed with invasive breast cancer and/or ductal carcinoma in situ, and 56 (6.2 %) with BBD. Women with high familial risk were significantly more likely to be diagnosed with breast cancer [odds ratio (OR) = 2.84, 95 % confidence interval (CI) 1.50-5.38] than low/moderate risk women, particularly if diagnosed at age ≥50 (OR = 2.99, 95 % CI 1.37-6.56) or screened with mammography (OR = 3.33, 95 % CI 1.54-7.18). High risk women were more likely to be diagnosed with BBD (OR = 1.94, 95 % CI 1.03-3.66). Level of familial risk was not associated with prognostic features. Cancers among unscreened women were larger (OR = 9.72, 95 % CI 1.01-93.61) and diagnosed at stage II or above (OR = 7.80, 95 % CI 1.18-51.50) compared with screen-detected cancers. Screening mammography may be effective for women with a first-degree family history of breast cancer, irrespective of level of familial risk.
authors.affiliation: Division of Prevention and Cancer Control, Cancer Care Ontario, 620 University Avenue, Toronto, ON, M5G 2L7, Canada, meghan.walker@cancercare.on.ca.
authors.forename: Meghan J
authors.initials: MJ
authors.lastname: Walker
authors.forename: Lucia
authors.initials: L
authors.lastname: Mirea
authors.forename: Kristine
authors.initials: K
authors.lastname: Cooper
authors.forename: Mitra
authors.initials: M
authors.lastname: Nabavi
authors.forename: Gord
authors.initials: G
authors.lastname: Glendon
authors.forename: Irene L
authors.initials: IL
authors.lastname: Andrulis
authors.forename: Julia A
authors.initials: JA
authors.lastname: Knight
authors.forename: Frances P
authors.initials: FP
authors.lastname: O'Malley
authors.forename: Anna M
authors.initials: AM
authors.lastname: Chiarelli
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001943:Breast Neoplasms / Q000175:diagnosis / Q000235:genetics*; D002278:Carcinoma in Situ / Q000175:diagnosis / Q000235:genetics*; D018270:Carcinoma, Ductal, Breast / Q000175:diagnosis / Q000235:genetics*; D055088:Early Detection of Cancer; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008327:Mammography; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D009864:Ontario; D010375:Pedigree; D011379:Prognosis; D012042:Registries; D012307:Risk Factors; D047368:Tumor Burden